// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_TRACK_METRICS_HOST_H_
#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_TRACK_METRICS_HOST_H_

#include <stdint.h>

#include <map>
#include <string>

#include "base/time/time.h"
#include "content/public/browser/browser_message_filter.h"

namespace content {

// Responsible for logging metrics about audio and video track
// lifetimes. These are based on messages from the renderer that are
// sent when tracks are created and destroyed. Unfortunately we can't
// reliably log the lifetime metric in the renderer because that
// process may be destroyed at any time by the fast shutdown path (see
// RenderProcessHost::FastShutdownIfPossible).
//
// There is one instance of this class per render process.
//
// If the renderer process goes away without sending messages that
// tracks were removed, this class instead infers that the tracks were
// removed.
class MediaStreamTrackMetricsHost
    : public BrowserMessageFilter {
public:
    explicit MediaStreamTrackMetricsHost();

protected:
    ~MediaStreamTrackMetricsHost() override;

    // BrowserMessageFilter override.
    bool OnMessageReceived(const IPC::Message& message) override;

private:
    void OnAddTrack(uint64_t id, bool is_audio, bool is_remote);
    void OnRemoveTrack(uint64_t id);

    // Information for a track we're keeping in |tracks_|. |is_audio|
    // specifies whether it's an audio or video track, |is_remote|
    // specifies whether it's remote (received over a PeerConnection) or
    // local (sent over a PeerConnection). |timestamp| specifies when
    // the track was connected.
    struct TrackInfo {
        bool is_audio;
        bool is_remote;
        base::TimeTicks timestamp;
    };

    void ReportDuration(const TrackInfo& info);

    // Values are unique (per renderer) track IDs.
    typedef std::map<uint64_t, TrackInfo> TrackMap;
    TrackMap tracks_;
};

} // namespace content

#endif // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_TRACK_METRICS_HOST_H_
